Semiconductor device fabrication often involve multiple steps that may require that at least part of the device be strongly secured at times, such as to a substrate. For example, when transporting a partially-fabricated semiconductor device, it is desirable that the device to be secured to the substrate strongly enough so that it does not shift or become detached from the substrate. Similarly, it is also desirable for the device to be secured during certain fabrication processes. One such process is laser lift-off (LLO), which is used to detach semiconductor devices from a substrate they are chemically adhered to. During LLO, a laser is focused on the interface of a substrate and base of the semiconductor device, often sapphire and gallium nitride, respectively. As the laser heats the interface, the bonds at the interface are broken, and the substrate can subsequently be removed. However, the devices need to be kept in place during the LLO process to avoid damaging the devices.
LLO may be part of a larger “chip transfer” process through which semiconductor device chips are removed from one substrate and placed onto another. Adhesive tapes are conventionally used for chip transfer processes and may be heat- or UV-release materials. However, such tapes are not suitable for ultra-fine-pitch interconnects (e.g., <10 μm pitch, <5 μm diameter, <5 μm height). Adhesive tapes are only able to provide a single level of adhesion, which is often too strong and prevents reliable chip release. Smaller devices especially may be damaged upon removal when the adhesion strength is too high. Alternatively, if the adhesion strength is too low, the devices may be disrupted during transportation or processing (such as LLO). Furthermore, adhesive tapes are highly flexible, which can cause chip misalignment during and after the transfer process.